This SCR timer was found in an old English documentation. The SCR can be the TUIC106 and modern equivalent transistors like the BC557 for TR1 and BC547 for the others.
We found this circuit in the June 1992 issue of Radio Electronics magazine. The sensor is a common...
This circuit converts a positive CMOS supply voltage to a negative one. We found it in a 90s...
This tone control was obtained from the CA3140 datasheet, originally created by RCA. The CA3140...